Share 'Ethics of Spending Time Outdoors'

I was wondering what some of the ethics are to refrain from damaging the environment or disturbing animals while going hiking, camping, exploring, whatever.
I can think of a few.. They may need tweaking, though.
Put stones around your fire, watch it carefully, put it out when you're done.
Don't leave anything behind, and don't take what you don't need from the forest. [Preferably ask for permiss…